This application relates to integrating optical and electrical components on a silicon substrate. Silicon integrated circuits (“ICs”) have dominated the development of electronics and many technologies based upon silicon processing having been developed over the years. Their continued refinement led to nano-scale feature sizes that can be important for making CMOS (complementary metal-oxide-semiconductor) circuits. On the other hand, silicon is not a direct-bandgap material. Although direct-bandgap materials, including III-V compound semiconductor materials, have been developed, there is a need in the art for improved methods and systems related to photonic ICs utilizing silicon substrates.